The Environmental Protection Agency on May 14 released a pre-publication version of its proposed rule to revisit the unmanaged combustion residual leachate (CRL) provision in the 2024 Steam Electric Effluent Limitation Guidelines (ELG) rule.
Once the proposal is published in the Federal Register, there will be a 30-day comment period.
APPA plans to file comments on this proposal, and staff welcomes members' input on the proposed rule. Please send your feedback to Carolyn Slaughter (policy@publicpower.org) as soon as possible.
EPA’s regulations applies to two types of unmanaged CRL that are considered distinct from CRL and defined as:
• Discharges of pumped unmanaged CRL: CRL that has leached from a landfill or impoundment into the subsurface and mixed with groundwater, after which it has been captured and pumped to the surface for discharge directly to a waters of the United States (WOTUS).
• Functional equivalent of a direct discharge of unmanaged CRL: CRL that has been determined, by the permitting authority, to be the functional equivalent of a direct discharge to WOTUS through groundwater.
This proposal evaluates three regulatory options and identifies one preferred option.
Under the preferred option, EPA would modify section 423.13 to clarify that any new unmanaged CRL best available technology economically achievable (BAT) requirements would not extend to retired plants closed by the effective date of the 2024 ELG (July 8, 2024).
In all three regulatory options, the EPA proposes to codify additional definitions to clarify the applicability of the unmanaged CRL limitations.
EPA proposes to define a “closed coal combustion residuals waste management unit” at 40 CFR 423.11(gg) to provide clarity as to which impoundments and landfills meet the criteria of being closed.
EPA is also proposing to further clarify the applicability of the effluent limitations with new provisions at 40 CFR 423.13(l)(3).
The first provision states that the effluent limitations in this subcategory do not apply to retired power plants, and that case-by-case BAT limitations based on the permitting authority’s best professional judgment (BPJ) continue to apply.
The second provision proposes that unmanaged CRL limitations do not apply to landfills closed by the 2024 ELG’s effective date of July 8, 2024, and that case-by-case BAT limitations based on BPJ continue to apply.
EPA proposes to clarify in section 423.13(l)(2)(ii)(B) that BAT limitations based on BPJ apply to unmanaged CRL generated before the effective date of the ELG rule.
The three regulatory approaches for addressing unmanaged combustion residual leachate are each based on different treatment technologies and management methods. EPA is requesting public comment not only on the specific issues identified in the proposal, but also on the overall rulemaking, including the data, assumptions, BAT determinations, effluent limits, and alternative approaches used to develop the options.
The proposal also includes a specific data request. EPA’s data request asks stakeholders to provide targeted information to support a future reconsideration of other waste streams in a Phase III rulemaking. Specifically, EPA is seeking input on any facilities or generating units missing from the industry profile, updated flue gas desulfurization flow rates, CRL flow rates for post-2015 waste management units, and pilot test performance data.
See EPA’s ELG website to review the technical support, economic analysis, and environmental assessment memoranda.
APPA said its staff is still reviewing the proposal and will soon follow up with a more detailed summary of the proposed rule.
